There are many ways to swap two numbers without using a third variable.
# 1. Using arithmetic operators


The arithmetic operators for *addition and subtraction* can be used to perform the swap without using a third variable.

#include <iostream>
using namespace std; 
  
int main() 
{ 
  int x = 10, y = 50; 

  x = x + y; // x = 60
  y = x - y; // y = 10
  x = x - y; // x = 50
  cout << "After Swapping: x = " << x << ", y = " << y; 
} 
  

x = 10
y = 50

x = x + y   # x = 60
y = x - y   # y = 10
x = x - y   # x = 50
print("After Swapping: x =", x, " y =", y); 

Python

import java.*; 
  
class Swap { 
    public static void main(String a[]) 
    { 
        int x = 10; 
        int y = 50; 
        x = x + y;  // x = 60
        y = x - y;  // y = 10
        x = x - y;  // x = 50
        System.out.println("After swaping:"
                           + " x = " + x + ", y = " + y); 
    } 
} 

Java

Similarly, *multiplication and division* can be used to perform the swap without using the third variable.

#include <iostream>
using namespace std; 
  
int main() 
{ 
  int x = 10, y = 50; 

  x = x * y; // x = 500
  y = x / y; // y = 10
  x = x / y; // x = 50
  cout << "After Swapping: x = " << x << ", y = " << y; 
} 
  

x = 10
y = 50

x = x * y   # x = 500
y = x / y   # y = 10
x = x / y   # x = 50
print("After Swapping: x =", x, " y =", y); 

import java.*; 
  
class Swap { 
    public static void main(String a[]) 
    { 
        int x = 10; 
        int y = 50; 
        x = x * y;  // x = 500
        y = x / y;  // y = 10
        x = x / y;  // x = 50
        System.out.println("After swaping:"
                           + " x = " + x + ", y = " + y); 
    } 
} 

# 2. Using Bitwise XOR
The result of the bitwise XOR operator is $1$ if the corresponding bits of two operands are opposite. It is denoted by `^`.


#include <iostream>
using namespace std; 
  
int main()
{
  int x = 10, y = 50;
 
  x = x ^ y;
  y = x ^ y;
  x = x ^ y;
 
  cout << "After Swapping: x = " << x << ", y = " << y; 
}
  

How to swap two numbers without using a third variable

Using arithmetic operators or Bitwise XOR can effectively swap two numbers without a third variable.